Skip to main content

Intro

calchylus is a computer installable Hy module that is used to evaluate, and furthermore through this documentation, shine light to the basics of Lambda calculus (also written as λ-calculus).

Lambda calculus is a formal system in mathematical logic for expressing computation that is based on function abstraction and application using variable binding and substitution.

The target audience is those who:

  1. are interested in the theory and the history of the programming languages

  2. may have or are interested to gain some experience in Python and/or Lisp

  3. who wants to narrow the gap between mathematical notation and programming languages, especially by means of logic

Andrew Bayer writes in his blog post about formal proofs and deduction:

Traditional logic, and to some extent also type theory, hides computation behind equality.

Lambda calculus, on the other hand, reveals how the computation in logic is done by manipulation of the Lambda terms. Manipulation rules are simple and were originally made with a paper and a pen, but now we rather use computers for the task. Lambda calculus also addresses the problem, what can be proved and solved and what cannot be computed in a finite time. Formally these are called the decidability and the halting problem.

Beside evaluating Lambda expressions, calchylus module can serve as a starting point for a mini programming language. Via custom macros representing well known Lambda forms, calchylus provides all necessary elements for boolean, positive integer, and list data types as well as conditionals, loops, variable setters, imperative do structure, logical connectives, and arithmetic operators. You can build upon that, for example real numbers, even negative complex numbers if that makes any sense. Your imagination is really the only limit.

Finally, when investigating the open source calchylus implementation that is hosted on GitHub , one can expect to get a good understanding of the higher order functions and the combinatory logic, not the least of the fixed point combinator or shortly, ϒ combinator.

Quick start

For people willing to get hands quickly on coding:

Install

$ pip install calchylus

Open Hy

$ hy

Import

(require [calchylus.lambdas [*]])

Initialize

(with-alpha-conversion-and-macros L ,)

Lambda dance

(L x y , (x (x (x (x (x y))))) a b) ; output: (a (a (a (a (a b)))))
(FIBONACCI SEVEN x y) ; output: (x (x (x (x (x (x (x (x (x (x (x (x (x y)))))))))))))

Documentation

For full documentation, see: calchylus.readthedocs.io

Metadata

Release files for calchylus 0.1.25

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for calchylus 0.1.25
File Size Uploaded Provenance
calchylus-0.1.25.tar.gz 12.4 kB Without provenance Details

Release files / calchylus-0.1.25.tar.gz

Download URL calchylus-0.1.25.tar.gz
Size 12.4 kB
Tags Source
SHA-256 checksum
How to use checksums
c610adc33bb9b1ca1558fabe3a268e0523bd1d38787b1d3f2682502e9a4ce12f
BLAKE2b-256 checksum
How to use checksums
361d0d8bc7a2c5a12fd061578bf11d21421beaff91c5f59a34140a7db88d01f5
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via Python-urllib/2.7

Security for calchylus 0.1.25

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

No provenance found

None of the files in this release were uploaded with provenance metadata.

A note on package security

PyPI is a repository for distributing packages, not a service for auditing them. While third-party security researchers and our staff do their best to detect and remove malicious packages, PyPI cannot guarantee the quality, security or suitability of any given package.

To learn more about protecting yourself from malicious actors, visit our package security documentation.

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page